G27 Pedals not working as they should all of a sudden!

After years of trouble free use, my G27 is behaving oddly. It seems like the brake pedal is sticking which restricts the throttle. So, in a race, I lose the ability to accelerate, and this is only rectified by tapping on the brake pedal.
The issue can be seen easily in F1 2016 graphic showing the brake and accelerator input. Sometimes the brake shows a flickering when there is no pressure on the pedal. As I said, then , a quick tap on the brake pedal resolves the situation for a few seconds.
Any suggestions about this issue?
How can I troubleshoot this? If it is the pedals, then a set can be bought on eBay for around £90.
Could it be connections needing a clean out?
Any help appreciated!